Vol.24, N°5 (2024) - Article 7
Diversity of Phytophthora palmivora and Trichoderma sp. strains in cocoa orchards in 3 regions of Côte d'Ivoire
Cocoa black pod disease, caused by Phytophthora sp. leads to yield losses. In order to remedy such losses, the use of an antagonistic fungus such as Trichoderma is recommended. This study aims at highlighting a diversity of Phytophthora palmivora and Trichoderma spp. strains in cocoa orchards in Côte d’Ivoire for better biological control of Phytophthora palmivora, the causative agent of cocoa black pod disease. To this end, soil from the cocoa rhizosphere, healthy cocoa pods, and cocoa pods affected by black pod disease were sampled. Trichoderma sp. and Phytophthora sp. were isolated from soil and black pod disease-affected pods, respectively. PCR, amplicon sequencing and phylogenetic demarcation analyses made it possible to characterize Phytophthora and Trichoderma species. Three Phytophthora palmivora morphotypes and three Trichoderma species (T. harzianum, T. asperellum, and T. virens) found in cocoa orchards were characterized. High nucleotide similarity (98.5 % to 99.55 %) was observed between the DNA sequences of these fungal strains and P. palmivora and Trichoderma spp. isolates reported in India and Côte d'Ivoire. Knowing the diversity of these fungal strains can contribute to improving cocoa yield in Côte d’Ivoire through the efficient control of Phytophthora palmivora, the causative agent of cocoa black pod disease.